Archive for May, 2013

Since there was not nearly as much study on interval training for the bike as there has been with running, I adapted my running training over to the bike. For marathon training I found mile repeats and half mile repeats to be a good workout, while doing 400 meter repeats for a short race. So on the bike I used 7 minute or 3.5 minute intervals followed by half that time for a rest interval, and would repeat 4 times. Many cyclists use a much short interval length. Of course the length of the interval, it’s intensity, and the rest interval, will all be a factor on what aspect you are trying to improve. Some research suggests an Ultimate Interval length based off your T-Max.

Before I get into the details, let me first make a case of why you should have a power meter to do this, although at the end I do offer some suggestions for those who do not have a power meter.

Use a Power Meter

With running, it is easy to see your progress by watching your pace for the interval splits. But with a bike, your speed is dependent on much more than just how much effort your are putting in. I tried to use a repeatable, mostly circular course to cancel out the effects of wind and incline. I figured if I averaged my speed during all the intervals that would be an indication of my fitness. However since I started to train with a power meter, I see that my prior approach is not sufficient. Take a look at this graph of four workouts done during the same year. If I based my estimate only on speed I would have thought I had declined during the last interval workout, but I actually improved by looking at the average power of the intervals.

The Ultimate Interval

Now that I have the advantage of using a Power Meter, I can change the interval approach and not try to just do the same course and interval length. Some studies point to what is referred to as T-Max interval as the basis for the ultimate interval. See this article in Bicycling Magazine.

Find Your T-Max

1. First you need to determine your Peak Power Output (PPO) by starting out cycling at 100 watts, increasing your power by 30 watts every minute until you reach exhaustion. You can go by your own feeling on what that point is, or some use a benchmark as when your cadence drops below 60 rpm.

2. Rest for one or two days, then after a warmup, start your timer and ride at your previously determined PPO until you can no longer sustain that power level. The amount of time you were able to hold your PPO is your T-Max. For most people that is around four to six minutes.

3. For the Ultimate Interval, use 60% of your T-Max for the interval length and twice that for the rest interval. So if you were able to hold your PPO for 6 minutes, you would use an interval length of 3.5 minutes followed by a rest interval of 7 minutes. This is the opposite of what I have been doing.

4. When doing the intervals take your power to your PPO and hold it there for the interval length (60% of your T-Max), then rest for twice the length, letting your heart rate decline down to about 60% of your maximum heart rate.

5. Start out with two to three intervals, doing two sessions a week. Try to build up to six to eight sets twice a week, with at least two days of spinning or rest between.

No Power Meter?

Without a Power Meter you will need to just use a nominal interval length, in the range of 2.5 to 3.5 minutes and a rest interval twice as long. When doing the intervals take your heart rate to 95-100 percent of your maximum heart rate. The recovery period should be at 60% of your maximum heart rate. My maximum heart rate is 176 so for the interval I would try to get over 167 bpm and for the rest interval I would be at 105 bpm, which is pretty much how I have been doing intervals.